A variety of techniques exist to combine multiple exposures of a scene into a single image. One technique is High Dynamic Range (HDR) imaging, which requires utilizing a high dynamic range of a digital image capture device. HDR images typically have a higher range of expanded intensities than any display device, include a great deal of information, and require a special format for storage in comparison to normal (non-HDR) images. Another technique is exposure fusion. Exposure fusion fuses together bracketed exposures of different images that are all within the normal dynamic range of a digital image capture device. During fusion, different exposures of a scene are fused together to combine the best parts of each of the different exposures in a single fused image. Exposure fusion is a very computationally intensive operation. Conventionally, exposure fusion is performed by central processing units and may, because of the computational intensity, take several minutes to fuse two or three exposures into a single fused image. Fusing together more images takes even longer. Because of this, exposure fusion is not conventionally viewed as a real-time or near-real time process. Instead, exposure fusion is typically performed post-processing.
There are some drawbacks to performing exposure fusion in a post-processing environment. First, since numerous images are captured to be fused together later, a large amount of storage may be required on the electronic device that captures the images. This can drive up the cost of the electronic device. Alternatively, a communicative coupling from an image capture device to a remote storage may be used to alleviate the need for large amounts of onboard storage. However, in some locales, a reliable (or any) communicative coupling to a remote storage may be unavailable. Additionally, since the ultimate results of a fused image are not available in real-time, it will either take a long time to capture and fuse images on location, or a risk must be taken that the captured exposures of a scene are sufficient to successfully post-process a fused image of the desired quality. In the case of post-processing, lack of sufficient exposures may cause expensive and time-consuming re-work to acquire the needed exposures of the scene.